I plan to max the 401(k) contribution this year. Which is better...to max it within the first six months or spread it over 12 months?

2gs

Assuming that you believe that you can't know what the market will do, odds are that your return will be greater if you invest it in six months rather than 12 months. However, spreading it over 12 months is slightly less risky.

My personal recommendation is to invest your money as soon as it's available. If you make a habit of continually doing this rather than holding it back, you will almost certainly be better off in the long run.